This application discloses an invention which is related, generally and in various embodiments, to a system which includes pressurized load cells.
Pressurized load cells have been utilized with tire/wheel combinations for a variety of vehicles including automobiles, motorcycles and all-terrain vehicles. For a given tire and wheel combination of a vehicle, the pressurized load cells (1) fill the void between the barrel of the wheel and the interior surface of the tire and (2) operate to maintain the tire load deflection or loaded ratio if the tire experiences a complete loss of pressure, and thus help the vehicle maintain control and mobility.
Despite the potential advantages of using pressurized load cells with tire/wheel combinations, the use of pressurized load cells with tire wheel combinations has been severely limited. The limited use is generally attributed to (1) the inefficiencies and difficulties associated with the pressurized load cells installation process and (2) the limited “give” of a tire having pressurized load cells positioned within the tire cavity.
Regarding the installation process, each load cell is typically partially inflated, then inserted one-by-one into the cavity of the tire until the cavity is filled with the partially inflated load cells (the partially inflated load cells form a substantially continuous ring). Next, each of the load cells is brought up to a higher pressure which is common to all of the load cells. The tire, which has the pressurized load cells positioned in its cavity, is then mounted to the wheel. The installation process requires a lot of steps, is relatively time consuming, is very susceptible to one or more of the load cells moving out of position or even falling out of the tire cavity before the tire is mounted to the wheel, and is generally not feasible for a high volume application.
Regarding the limited “give” of a tire having pressurized load cells positioned within the tire cavity, the pressurized load cells occupy a certain volume of the tire cavity. As the tire pressure drops, the ability of the tire to “flatten” and increase the amount of external surface area of the tire in contact with the ground is limited not only by the deflection of the tire, but also by the deflection of the pressurized load cells. Due to the limited “give” of such tire/wheel combinations, there are not well-suited for applications which require substantial deflection of the tire (e.g., climbing an obstacle like a vertical step which is taller than ⅓ of the outside diameter of the tire).